Pictures of Hunter S. Thompson and Ralph Steadman in the Seventies when they began working together. / Photos by Ralph Steadman, Courtesy of Sony Pictures Classics

by Mike Snider, USA TODAY

by Mike Snider, USA TODAY

Artist Ralph Steadman backed a winning horse on his first trip to the Kentucky Derby back in 1970: the late gonzo journalist Hunter S. Thompson.

The British illustrator, profiled in the documentary For No Good Reason (opening Friday in New York and May 2 in L.A.), was hired to illustrate Thompson's article The Kentucky Derby is Decadent and Depraved by Scanlan's Monthly editor Warren Hinckle. He paired the two because, says Hinckle, Steadman was "a very evil-minded twisty kind of guy. They ended up going through this haze of alcohol and drugs and madness."

The illustrations and prose of "a drunken mob scene," as Thompson would chronicle it, turned out to be the first collaboration in a four-decade run. "We went on a binge for the week. We sort of went along with whatever happened," says Steadman in the film.

For No Good Reason chronicles the life of Steadman, now 77, and his exploits with Thompson. Over the years they teamed to cover events including the 1970 America's Cup and the 1974 "Rumble in the Jungle' championship boxing match between George Foreman and Muhammad Ali, and collaborated on countless political articles.

But the Derby piece, part of the artist's first visit to the United States, "became the beginning of gonzo," Steadman says. "I met up with the one man I needed to meet in the whole of America to work with."

The film establishes that the visual report is as vital to gonzo journalism as the words. "The essence of gonzo journalism is when you go to cover a story but you don't cover the story, you become the story," Steadman says in a phone interview from his home in Kent, England. "That's how it should be. It's a couple of journalists working together."

The documentary captures Steadman's creative process, starting with the initial flick of an ink-swollen brush that results in a Rorschach-style blot on the canvas. "It might just lead somewhere," he says in the film.

Viewers get up-close footage because director Charlie Paul asked Steadman 15 years ago if he would install a camera in his studio. Steadman and Thompson caught Paul's attention as an art student because they were "the first punks," he says. "What they were doing â?¦ was to kick back at all the banality that was being forced down our throats."

Paul, who also is a painter, animated some of Steadman's illustrations for the film. "I wanted to find a way of not only interpreting Ralph's art, but bring it to a new audience and give it new life and new vitality," he says.

Thompson, who committed suicide in 2005, is ever-present in video clips and in the form of his friend Johnny Depp, who interviews Steadman on camera and narrates some of Thompson's articles. The actor starred in two films based on Thompson's works, Fear and Loathing in Las Vegas and The Rum Diary, and, for Paul, he serves as "the framer that contains the art, as well as a torchbearer of Hunter's."

When relating his tales of Thompson, Steadman delivers a spot-on vocal imitation of his colleague. When he would ask Thompson why they were covering an event, the writer would say in his gravelly mumble, "For no good reason, Ralph."

Coming to the United States, Steadman found many subjects on which to vent artistically. The film highlights his skewerings of President Nixon drowning in sweat and Henry Kissinger crouching like the giant spider Shelob in a Lord of the Rings-esque web.

"I think America was where all that was going wrong in the world was being nurtured," Steadman says in the film. "It seemed to me that they needed attacking. ... It had fallen to me to do this. It was my duty to change the world. I had always thought I wanted to change the world. Now was the moment."

While they were kindred spirits, Steadman in some ways could be more extreme and dangerous than Thompson, says Rolling Stone publisher Jann Wenner. "He was willing to say anything about anybody (and when) his moral sensibility was affronted he wouldn't stop ... (and would go) beyond the limits of what was appropriate.''

The film dispels any inkling of Steadman as a one-trick pony. Paul reveals a depth in Steadman that is analogous to the multiple dimensions in the lunatic-fringe images he creates.

The artist's creative influences include Rembrandt, Picasso and Francis Bacon, but his approach was likely galvanized by canings he took from an authoritarian schoolmaster. His other pursuits include illustrating a 50th anniversary printing of the Universal Declaration of Human Rights and working on a sequel to his 2012 book called Extinct Boids. (See them and Steadman's other works at RalphSteadman.com.)

The film ends on a melancholy note as Steadman tells Depp that he doesn't feel he's proven himself an artist and is still thought of as a cartoonist.